Results of the EDMOND and SonotaCo united databases

The first results of the united databases analysis, in which we studied identification of the meteor shower from IAU MDC working list, are presented. Using the D-criterion of orbits similarity method we identified 548 meteor showers from a total of 757 meteor showers in the list. The united largest databases EDMOND (European video MeteOr Network Database) and SonotaCo contain 412 414 multi-station orbits of meteors.

Introduction

The European viDeo Meteor Observation Network (EDMONd) and the European video MeteOr Network Database (EDMOND) has been established only recently (Kornoš et al., 2014a,b). The network originates from spontaneous cooperation between observers in several parts of Europe. The EDMONd Network has been enlarged in recent years and at present consists of observers from the following national networks (in alphabetical order): BOAM (Base des Observateurs Amateurs de Metéores, France); BosNet (Bosnia); CEMeNt (Central European Meteor Network, cross-border network of Czech and Slovak amateur observers); CMN (Croatian Meteor Network or Hrvatska Meteorska Mreza, Croatia); FMA (Fachgruppe Meteorastronomie, Switzerland); HMN (Hungarian Meteor Network or Magyar Hullócsillagok Egyesulet, Hungary); IMO VMN (IMO Video Meteor Network); MeteorsUA (Ukraine); IMTN (Italian amateur observers in Italian Meteor and TLE Network, Italy); NEMETODE (Network for Meteor Triangulation and Orbit Determination, United Kingdom); PFN (Polish Fireball Network or Pracownia Komet i Meteorów, PkiM, Poland); Stjerneskud (Danish all-sky fireball cameras network, Denmark); SVMN (Slovak Video Meteor Network, Slovakia); and UKMON (UK Meteor Observation Network, United Kingdom). Last established network (January 2014) is on southern hemisphere – BRAMON (BRAzilian MeteOr Network). It´s independent network of EDMOND database, its task is to map the activity of meteor showers in the southern hemisphere. Nowadays, due to the international cooperation, meteor activity is monitored over almost the entire Europe. Consequently, in recent years, multi-national networks of video meteor observers have contributed many new data. As a result, the latest version of EDMOND database (v5.0, January 2015) contains 3 275 335 single meteors and 221 639 orbits collected from 2001 to 2015. Data from 2015 are incomplete, observations of IMO VMN from 2015 are not included yet. SonotaCo network (SonotaCo, 2009) has been working since 2004 in Japan, the catalog of multi-station orbits was established since 2007. Nowadays, it contains 190 775 orbits collected from 2007 to 2014.

Methodology

The main part of the orbit calculations from two or more stations is realized in the UFO Orbit software (Sonotaco, 2009). Data reduction is implemented in two steps. The first step is used in calculation of the orbits in UFO Orbit software. Only the combinations of the identical single-station meteors with time difference Δt < 5 sec are used and all meteors with duration dur < 0.1 sec are excluded. Multi-station trajectory qualitative criteria has to be meet as follows: maximum speed difference Δv < 7 km/s between the observations from two stations is accepted; empirically calculated multi-station trajectory quality parameter in the range QA > 0.15; height of the beginning and of the end of the meteor atmospheric trajectory H1 < 200 km and H2 > 15 km respectively. In this first step the unrealistic and low accurate trajectories are excluded. In the second step the specific reduction criteria are applied to already calculated orbits. The angle of observed trajectory has to be Qo > 1°, the convergence angle Qc > 10°, the difference between two poles of ground trajectory ΔGP < 0.5° and the difference between unified velocity and velocity from one of the stations Δv12% < 7.07% (Kornoš et al., 2013b). Assigning of the derived meteor trajectories to the mean meteor stream orbit is based on the D-criterion of orbits similarity, which compares orbital elements of the meteors (i.e. e, q, i, ω and Ω). In the case of assigning potential members of the meteor showers from IAU MDC working list (Jopek et al., 2014) the Southworth-Hawkins criterion DSH (Southworth and Hawkins, 1963) was used. The limit value of the criterion was set DSH < 0.1 for meteor showers from IAU MDC working list.

Results

The total number of assigned orbits to the meteor showers from IAU MDC working list was 153 990 (with DSH < 0.1). At least one orbit has been assigned to 548 meteor showers from a total of 757 in the list. More than 100 orbits have 178 meteors showers, more than 500 orbits have 29 meteors showers and finally more than 1000 orbits have 18 major meteor showers.

Picture 1 – Map of the radiants of the multi-station orbits belonging to the meteor showers from IUA MDC working list. Map is in the equatorial coordinate system, the center is located at position RA=0°/DEC=0°.

Picture 2 – Map of the radiants of the multi-station orbits belonging to the meteor showers from IUA MDC working list. Map is in the equatorial coordinate system, the center is located at position RA=180°/DEC=0°.

Picture 3 – Map of the radiants of the multi-station orbits belonging to the meteor showers from IUA MDC working list. Map is in the ecliptical coordinate system, the center is located at position LON=270°/LAT=0°. Ecliptical longitude of the Sun is subtracted from the ecliptical longitude of the orbits radiant.

Table 1 – The list of meteor showers from IAU MDC working list with more than 500 multi-station. Remark: * meteor shower is member of the Taurids complex.